Code execution via unchecked RTSP rewrite
Published Aug 19, 2026 · Updated Aug 20, 2026
Buffer overflow in libalias in FreeBSD allows attackers to execute code via crafted outbound RTSP traffic during NAT translation. The RTSP handler rewrites payloads into a fixed-length stack buffer without checking that the rewritten data fits that buffer or the original packet length. Reachability requires a host behind a NAT gateway that uses libalias on outbound TCP or UDP traffic to ports 554 or 7070; successful exploitation can execute code in the kernel through ipfw(4) NAT or in the root natd(8) process.
Summary
What happened
Buffer overflow in libalias in FreeBSD allows attackers to execute code via crafted outbound RTSP traffic during NAT translation. The RTSP handler rewrites payloads into a fixed-length stack buffer without checking that the rewritten data fits that buffer or the original packet length. Reachability requires a host behind a NAT gateway that uses libalias on outbound TCP or UDP traffic to ports 554 or 7070; successful exploitation can execute code in the kernel through ipfw(4) NAT or in the root natd(8) process.
The record
- CVE
- CVE-2026-49420
- Published
- Aug 19, 2026
- Updated
- Aug 20, 2026
- Vendor
- The FreeBSD Project
- Product
- FreeBSD
- Classifications
- CWE-121, T1210
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 19, 2026CVE publishedPublication date reported by the CVE source.
- Aug 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=14.3-RELEASE <p16
- Affected versionversion=14.4-RELEASE <p7
- Affected versionversion=15.0-RELEASE <p11
- Affected versionversion=15.1-RELEASE <p1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo